Transformers are made of three main components. Which trio lists them correctly?

• A. Core, Windings, Insulating Fluid
• B. Core, Windings, Lightning Arrestor
• C. Laminations, Windings, Insulating Fluid
• D. Core, Insulation, Switchgear

Answer: (A)

The key idea is recognizing the three essential parts that let a transformer do its job: a magnetic core to provide a path for the magnetic flux, windings to carry the electrical currents and enable voltage transformation, and an insulating fluid that surrounds and cools the windings while providing electrical insulation. The core concentrates flux so the magnetic circuit is efficient; the windings create the voltages and are arranged so mutual inductance transfers energy between them; the insulating fluid (often oil) both insulates the windings from each other and the core and carries away heat, keeping the transformer from overheating. The other options mix in protective devices like surge arrestors or external equipment like switchgear, or treat laminations as a separate component, whereas the fundamental trio focuses on core, windings, and the insulating medium that also handles cooling.